The present disclosure generally relates to reciprocating compressors, and more particularly to reciprocating refrigerant compressors for cooling appliances.
Modern refrigerators typically include a closed refrigeration circuit having a compressor, an evaporator, a condenser, and a number of fans to direct cooled air into refrigeration compartments. Refrigerators typically function under multiple conditions, which may include long periods of low demand during which the compressor runs for a short period of time and remains off for a long period of time, as well as short periods of high demand during which the compressor runs steadily through the period of high demand (such as during meal preparation, frequent door openings, accelerated cooling modes, automatic icemaker use, and high ambient temperature, for example). Present refrigerator designs must have sufficient capacity to operate and supply the necessary cooling for high demand, and typically include a large single capacity compressor to meet the high demand. The requirement to satisfy high demand operation presents a difficulty to efficiently operate during low demand operation. A motor driving the compressor with displacement sufficient to meet high demand must be sized to supply the starting torque required for the compressor, which requires greater current (and thus, motor size) than steady-state torque. During periods of low demand, a compressor sized for high demand provides excess capacity, runs infrequently, and can lead to complications in high efficiency refrigerators, such as greater cyclic losses, power consumption, sweat, and compartment temperature fluctuation with low ice rate and reduced motor efficiency, for example. Accordingly, there exists a need for a refrigeration compressor arrangement to overcome these drawbacks.
Accordingly, it would be desirable to provide a system that addresses at least some of the problems identified above.